Revert of Improve how the column balancer handles top margins on floats. (patchset #3 id:40001 of https://codereview.chromium.org/2465363003/ )
Reason for revert:
Speculative revert to fix csspaint/invalidation-background-image.html failure on "WebKit Win7 (dbg)" bot.
Failed build:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win7%20%28dbg%29/builds/7961
Original issue's description:
> Improve how the column balancer handles top margins on floats.
>
> Float margins do not collapse with column boundaries, so we should make room
> for them after the break, if the border box of the float starts in the next
> column.
>
> Let the balancer work on the margin box of the float (and the border box for
> all other objects). For floats, we want to insert breaks before the
> margin-before edge, not the border-before edge. This lets us remove
> some special-code for unbreakable floats in InitialColumnHeightFinder, which
> was the only place that previously bothered about this.
>
> Changed how we determine which objects to process. We used to include the
> overflow both before and after the border box, but we really don't have to
> bother with content preceding it, since that shouldn't undergo fragmentation
> anyway.
>
> Discovered (one test regressed) that logicalHeightIncludingOverflow() also
> included clipped overflow, which certainly wasn't the intention. This didn't
> make much of a difference as long as the method was only called to check if we
> could skip re-layout. But now we also use it to determine the column height.
> Fixed it to only include visible overflow and renamed it to
> logicalHeightWithVisibleOverflow().
>
> Committed: https://crrev.com/7c82da727f64121aa34aa1decf82452c37ef7a2d
> Cr-Commit-Position: refs/heads/master@{#429245}
TBR=eae@chromium.org,mstensho@opera.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
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Review-Url: https://codereview.chromium.org/2468193002
Cr-Commit-Position: refs/heads/master@{#429265}
5 files changed
